Mon Aug 8, 12:00-1:00, 4750 Boelter Hall:

Traffic Shaping System Calls Using Threading by Appointment

Christoph Kirsch
University of Salzburg, Austria

Threading by Appointment (TAP) is a concurrent, thread-based
programming model.  Unlike traditional threads, TAP threads invoke
system calls by appointment only.  Time and duration of appointments
are determined by the TAP runtime system transparently through a
POSIX-compliant interface.  The TAP mechanism essentially implements
system call queueing using a given TAP policy that consists of a
strategy to make appointments, i.e., enqueue system calls, and a
logical clock to begin and end appointments, i.e., dequeue system
calls.  We propose a TAP policy that resembles traffic shaping in
network routers where system calls are treated as network packets.
The policy distinguishes system calls for network and disk I/O, and
gives priority to system calls invoked by short-running, interactive
threads rather than long-running, bulk threads.  We have implemented a
high-performance, user-space TAP library and benchmarked the library
using two multi-threaded, POSIX-compliant web servers.
Joint work with Petru Flueras and Harald Roeck.

About the speaker:  Christoph Kirsch received the Dipl.-Inform. degree
and the Dr.Ing. degree in computer science from Saarland University,
Saarbruecken, Germany, in 1996 and 1999, respectively.  From 1993
until 1999 he was with the Max Planck Institute for Computer Science
in Saarbruecken.  He then spent four years as Postdoctoral Researcher
at the Department of Electrical Engineering and Computer Sciences of
the University of California, Berkeley.  Since 2004, he is full
professor at the Department of Computer Science of the University of
Salzburg, Austria.  His research interests are in concurrent
programming and systems, virtual execution environments, and embedded
real-time software.  He has co-founded the ACM International
Conference on Embedded Software (EMSOFT) and served on the program
committees of OOPSLA, VEE, EMSOFT, and LCTES.

Hosts:  Rupak Majumdar and Jens Palsberg.